From the introduction to the description in German patent document 34 47 676, devices for the automatic control of a clutch are known in which the clutch is arrayed between an engine of a motor vehicle and a transmission, preferably to be shifted automatically.
The engagement and the speed of engagement is, as described, influenced by the speed increase of the engine and the instantaneous engine speed.
It is further known to utilize the amount of change of the engine speed due to the actuating speed of the gas pedal to control the engagement speed of the clutch.
Further, it is known from German patent document DE-OS 34 74 676 to store a maximum acceleration of the engine speed electronically for the determination of a clutch engagement speed and to compare it with an actually measured engine speed during acceleration, and to cause clutch disengagement or to leave the clutch disengaged at an equal or lower engine speed, or to cause clutch engagement when the actual engine speed is higher.
Since the procedure described occurs during relatively short periods, a smooth yet efficient start of a vehicle is assured. Furthermore, the life of the automatic clutch is extended, and the performance of the vehicle is improved, in that acceleration of the engine at idle is avoided. The slip of the partially engaged clutch is minimized. Finally, a rapid start of the vehicle is facilitated without overloading the engine. This arrangement may be quite suitable for application to a passenger car, but is not applicable to a utility vehicle such as a truck, because the response time of the described control is too slow. With the large diesel engines in utility vehicles, this slow response can lead to excessive engine speed or an excessive increase in torque. The rapid torque fluctuations arising upon clutch engagement give rise to unacceptable vibration in the sensitive drive trains of utility vehicles.